Is there any reason that I cannot use discarded Nv Objective lenses and eyepieces for my conversionon a P8079HP? I see that most use a 50mm f1.4 objective, but the ones I have worked for their respectiveNV devices. I am aware of the 35mm distance rule for the objectiveand the 25-60 rule for the eyepiece.Any advice?Thanks in advanceBruce